The central goal of this project is to study the early events whereby interferon (IFN) treatment of cells leads to the development of biological response(s). The antiviral action of IFN requires the expression of certain cellular genetic information. The aim of this project is to identify and characterize the gene products induced by IFN treatment and to use them as molecular markers to study the early events involved in IFN action. Studies carried out have revealed that IFN treatment induces the synthesis of a number of proteins in mouse and human cells. On various criteria, this induction seems to correlate with the development of the antiviral response as tested in human fibroblasts. We further plan to investigate the relationship between the IFN-induced polypeptides and the 2',5'-oligoadenylate synthetase and a protein kinase enzyme activity induced in various cell types after IFN treatment. The kinetics of their induction during IFN treatment and de-induction upon withdrawal of IFN in relation to the antiviral effect will be studied. Attempts will be made to raise antibodies against these IFN-induced polypeptides to investigate their involvement in the antiviral mechanism.